PREDICTION OF PLASTIC DEFORMATION FROM DEFLECTION MEASUREMENTS

In order to forecast the plastic deformation from deflection measurements, research into the relation between the curvature index of a pavement, determined from deflection measurements, and the stress situation, expressed in the average vertical stress or stress-invariants, in the two top layers of a three layer system is discussed. It is concluded that it is possible to determine the average vertical stress in the top layer of a three layer system based on the curvature index and that the thickness of the first layer of about 20 cm is unfavourable in connection with the origin of plastic deformation in that layer. (TRRL)